I want to create multiple gizmos and views of them, letting the views
overlap on the screen. In my searching, I came across references to an
MS-Win-style multiple document interface widget set, but the links were
all stale. P.32 of Grayson shows the creation of multiple toplevel
windows, and I figured that would be the ticket. So I coded that up,
but I have a problem with how to delete a data structure when the user
deletes the associated toplevel window by clicking on its X-button in
the upper right corner.
What I have right now is:
class BlockView:
def __init__(self, block, # Display is of a block
title, # for title bar
root, # ur-toplevel interface
destroyCB): # callback for when the window is
destroyed
self.tl = Pmw.MegaToplevel(root)
self.tl.bind('<Destroy>',
lambda event, self=self, destroyCB=destroyCB:
destroyCB(event,self))
...
The idea is that when the MegaToplevel is destroyed, BlockView sends a
'delete me' message to its creator via destroyCB. The creator then
deletes the BlockView from its lists.
However, Destroy events get sent for all the children of the new
MegaToplevel. I need to strain out all but one callback. I thought I
could do it by rewriting the lambda expression as
lambda event, self=self, destroyCB=destroyCB: event.widget is
self.tl and destroyCB(event,self))
but this never calls destroyCB. I tried rewriting the new test as
event.widget is self.tl.interior()
but that didn't activate, either. Obviously, I don't understand what
event.widget is, and Grayson's explanation of events isn't very
thorough. Can someone give me some hints here?
TIA
David Smith